1. Field of the Invention
The invention relates to methods of setting chocolates, chocolate-like compositions and products produced by same. More specifically, the invention relates to methods of setting chocolate using a rapid cooling step by the use of very low temperatures, high heat transfer rates and/or short cooling times, using a controlled moisture rewarm zone and/or using a broader range of temper to form set chocolate products. The invention also relates to novel chocolate products having improved bloom resistance, enhanced gloss and other advantageous characteristics.
2. Description of the Related Art
Documents and references pertaining to the field of this invention are cited in this disclosure with a full citation for each; and, each cited document is hereby incorporated by reference.
The unique flavor and mouthfeel of chocolate is a result of the combination of numerous components as well as the process of manufacture. Chocolate contains solid particles dispersed throughout a fat matrix (the term xe2x80x9cfatxe2x80x9d includes cocoa butter and milk fat). Similarly, chocolate-like compositions may also contain fats other than cocoa butter or milk fat. Accordingly, melted chocolate and chocolate-like compositions are suspensions of non-fat particles (e.g., sugar, milk powders and cocoa solids) in a continuous liquid fat phase. The fat phase of milk chocolate, for example, is typically a mixture of cocoa butter, a suitable emulsifier, and milk fat. Cocoa butter is typically the predominant fat in the chocolates.
Cocoa butter is a polymorphic material in that it has the ability to crystallize in a number of different crystal packing configurations (Wille and Lutton xe2x80x9cPolymorphism of Cocoa Butterxe2x80x9d, J. Amer. Oil Chem. Society, Vol. 43 (1966) pages 491-96). Six different polymorphic forms are generally recognized for cocoa butter. Forms I and II are produced, for example, by rapidly cooling melted untempered chocolate to low temperatures and are very unstable with low melting points. Forms III and IV melt at higher temperatures than Forms I and II but are not the most desirous forms for confectionery manufacture. Forms V and VI are the most stable forms of cocoa butter. It is desirable to have Form V as the predominant form in a well-tempered chocolate. Form V transforms slowly into Form VI after a period of time. Accordingly, chocolate processing is strongly linked to the crystallization and polymorphic behavior of the fat phase. Before chocolate can be satisfactorily processed from liquid to solid using conventional methods, it must be tempered after which it is gently cooled to form a set chocolate having a stable fat phase.
The most commonly used method of processing chocolate involves the following sequential steps:
A. complete melting of the chocolate fat phase;
B. cooling to the point of initial crystallization of the fat phase (i.e., below the melting point of the liquid fat phase);
C. crystallizing a portion of the liquid fat phase;
D. slight heating to melt out any unstable crystals that may have formed leaving from about 3 to 8 wt % as seeds for crystallizing the remaining liquid fat; and
E. gently cooling to set the chocolate, typically in a cooling tunnel.
During conventional chocolate processing, the chocolate mixture is initially melted at temperatures of about 45xc2x0 C. and tempered by cooling with agitation to about 29xc2x0 to 30xc2x0 C. The tempering of the chocolate results in a chocolate dispersion having fat crystals dispersed throughout the liquid fat phase. The chocolate suspension may then be further processed prior to setting by, for example, enrobing the chocolate onto an edible center or molding the chocolate. The chocolate is finally set into a form sufficiently solid for wrapping by gentle, controlled cooling.
Conventional tempering is the controlled partial precrystallization of the fat phase which is believed to be necessary to produce a stable solid form of the fat in the finished product. Therefore, one important object of tempering is to develop a sufficient number of stable seed crystals so that under appropriate cooling conditions the fat phase of the chocolate is able to crystallize into a stable polymorphic form. Tempering plays a key role in ensuring that the cocoa butter crystallizes in the stable form. xe2x80x9cChocolate must be properly tempered. Undertempered chocolate causes delayed setting in the cooler and adhesion to [processing equipment such as a] conveyor belt, and ultimately bad chocolate color and fat bloomxe2x80x9d (see Chocolate, Cocoa and Confectionery: Science and Technology, by Minifie, 3rd Ed., p. 218).
Although it is important that the chocolate is well seeded with stable forms of cocoa butter crystals, the tempered chocolate still contains a high proportion of liquid cocoa butter, estimated from about 92 to 97 wt % of the fat phase. This must be solidified in the cooling process so that the set chocolate can be wrapped and ultimately be completely solidified into a stable crystalline form. (see Chocolate, Cocoa and Confectionery: Science and Technology, by Minifie, 3rd Ed., p. 195).
In cooling tunnels used in commercial processing, the crystallization of the remaining liquid fat phase must take place without further treatment while the chocolate is setting. The setting of chocolate occurs when the material has already been enrobed or placed in a mold, for example. That is, the chocolate is set while not subjected to flow or mixing. It only takes a slightly lower temperature to complete the transition from the liquid to the solid state, since the tempered chocolate is already partially solidified (see Industrial Chocolate Manufacture and Use by S. T. Beckett, Second Edition, page 232). The purpose of conventional cooling tunnels is to make the chocolate sufficiently solid so that it may be wrapped at room temperature.
Conventional methods passively cool the chocolate to promote crystalline growth throughout the fat phase using cooling environments having operating temperatures between 10 and 20xc2x0 C. It In fact, conventional wisdom dictates that the liquid chocolate must not meet very cold air because it is believed to make the remaining cocoa butter unstable (see Chocolate, Cocoa and Confectionery: Science and Technology by Bernard W. Minifie, Third Edition, pages 212-221, particularly page 212). It is currently believed that the chocolate must be allowed to cool gently and not be subjected to aggressive cooling through exposure to low temperatures, as this has the effect of quickly drawing the cocoa butter up to the surface of the product, resulting in fat bloom (see Industrial Chocolate Manufacture and Use by S. T. Beckett, Second Edition, page 232).
With colder air more unstable crystals will be formed and the possibility of subsequent bloom developing is greater. It has been recommended that for the conventional forced circulation tunnel the air be brought in at a temperature not lower than 45xc2x0 F., preferably considerably higher. (Paper presented by Dr. Roy F. Korfhage, Ambrosia Chocolate Company, before the A.A.C.T. Atlanta Section, Feb. 24, 1967, pages 13-14.) It was previously believed that xe2x80x9ctoo cold too soonxe2x80x9d would result in products which would appear greasy as the warmer coating, under the prematurely hardened surface skin, will work its way to the surface in the heat transfer process. The preferred cooling system was a zoned system where the product entered the cooler at about 65xc2x0 F. (Principles of Cocoa Butter Crystallization, by Dimick, 45th P.M.C.A. Production Conference, 1991).
Accordingly, conventional cooling is relatively passive in that the heat transfer rate is low. A typical cooling tunnel cools a chocolate from a temperature of about 29-30xc2x0 to about 10-25xc2x0 C. in a period of time typically greater than about 7 minutes.
One disadvantage of the requirement that the chocolate be set by gentle cooling is the extended period of time resulting from the slow cooling. This results in either the requirement that the chocolate move slowly through the cooling zone, reducing the speed and efficiency of commercial chocolate processing lines, and/or requiring very long cooling tunnels to provide for slow cooling while maintaining a fast production line. Typical commercial cooling tunnels are on the order of 10 to 100 meters long depending on the size of the chocolate piece and the speed of the conveying belt. As a result, the buildings housing such facilities must be large enough to accommodate such tunnels. This greatly increases the capital requirements for any conventional commercial processing facility.
Yet another disadvantage of the prior methods of making chocolate confections is the inability to consistently make chocolate products having a high surface gloss. The surfaces of molded chocolates that were in contact with the mold have very high gloss compared with enrobed products made with the same chocolate composition produced without the use of a mold. It is believed that the chocolate wets the surface of ambient temperature molds thereby reducing the fat retraction from the surface that may occur during cooling. However, the use of a mold to form a chocolate product is much slower and less efficient than non-mold processes such as enrobing. A conventional enrobing line can achieve efficiencies up to 10,000 pieces/minute compared with 2,000 for molding lines. The inability to provide the high gloss and high detail comparable to that of a molded product without the use of a mold reduces commercial efficiencies of conventional chocolate processing facilities.
U.S. Pat. No. 3,229,647 to Drachenfels et al. relates to a method for processing chocolate compositions, masses and coatings comprising a step in which a flowable pre-heated mass is subjected in a storage container to a cooling process in order to produce fat crystals. The method involves subjecting a pre-heated heated chocolate mass to undercooling in contact with a cooling surface to 21-25xc2x0 C.
U.S. Pat. No. 5,275,835 to Masterson relates to a process for preparing chocolate-flavored confectionery compositions containing reduced calorie substitute fats using certain dynamic tempering conditions. An object of the patent is reducing the time needed for tempering flavored compositions. The method involves dynamically tempering the compositions by rapidly cooling from a non-crystalline state to a temperature of less than about 70xc2x0 F. (21.1xc2x0 C.) and then warming the composition to about 85xc2x0 F. (29.4xc2x0 C.) while subjecting the tempered composition to shear agitation and subsequently setting the tempered chocolate by cooling.
PCT Patent Publication WO 95/32633 to Aasted relates to a method for producing molded shells of fat-containing, chocolate-like masses wherein a mold cavity is filled with a mass and a cooling member having a temperature below 0xc2x0 C. is subsequently immersed in the mass to define a predetermined shell volume between the member and the mold cavity.
European Patent Application 0 589 820 to Aasted relates to a method for producing molded outer shells of fat-containing, chocolate-like masses wherein a mold cavity is filled with a tempered chocolate-like mass which solidifies from the mold cavity inwardly to form the outer shape of the shell, the temperature of the mold cavity being lower than the temperature of the tempered mass. The mold cavity is filled with a chocolate-like mass in an amount which is just slightly larger than the volume of the finished shell. A cooling member, which has preferably been cooled to xe2x88x9215 to xe2x88x9230xc2x0 C., is then immersed into the chocolate mass and kept in a fully immersed position for about 2 to 3 seconds. The chocolate-like mass will then solidify rapidly during crystallization from the cooling member and will readily release the cooling member, which can be lifted up and out of the mold cavity.
PCT Patent-Publication WO 94/07375 to Cebula et al. relates to forming fat-containing products such as chocolate in molds at temperatures at or below 0xc2x0 C. to provide unforced demolding.
U.S. Pat. No. 3,935,321 to Sakler et al. relates to the production of food products having at least an outer layer of a material which is heat liquified in the formation of the product and which crystallizes upon cooling to provide a glossy surface. This is achieved by subjecting the product to a corona current after the surface of the product has hardened to rapidly extract heat from the inner regions of the material.
U.S. Pat. No. 4,426,402 to Kaupert relates to a method and apparatus for producing chocolate forms using molding tools. During a injection step, the molding tool is cooled with a coolant, wherein one of the molding parts is maintained at about 20xc2x0 C., while the other is maintained at a substantially lower temperature of 0xc2x0 C. or less, such as about xe2x88x925xc2x0 C. Even lower temperatures, such as xe2x88x9210xc2x0 C. and even xe2x88x9220xc2x0 C., are disclosed as acceptable for still faster molding speeds if the formed chocolate body is carefully handled.
All of these references fail to teach or suggest methods of setting chocolate using a rapid cooling step without the use of a mold using low temperatures (5xc2x0 C. and below), high convective heat transfer coefficients and/or short times to provide an acceptable finished chocolate confection, i.e., bloom resistant, good gloss and hardness, etc. In fact, the related art teaches that setting chocolate using a rapid cooling step is to be avoided at all cost. The slow setting times of conventional methods greatly increases the time required for making chocolate products. The references also fail to teach or it suggest improved chocolate products having increased resistance to bloom and other advantageous properties, including potentially improved gloss and retention of fine detail and decoration, which is achieved while reducing the cooling times using the present invention. Moreover, the references also fail to teach or suggest methods which enable the setting of ultra-low temper chocolate.
Thus, the development of methods which increase the speed and efficiencies of chocolate processing lines, while at the same time providing improved products, is a highly valuable addition to the art.
There has also been a long felt desire to produce a heat stable or heat resistant, enrobed chocolate product. As discussed above, ordinary chocolate is composed primarily of fats or fatty substances, such as cocoa butter, in which there are dispersed non-fat products such as cocoa components, sugars, proteins, etc. Therefore, since chocolate is primarily constituted by fat bodies, its melting temperature is relatively low. This means that ordinary chocolate is not particularly resistent to summer temperatures or the heat of tropical countries. In fact, many chocolates have a greasy or oily texture when handled and sometimes even melt when picked up or handled. Therefore, a need exists for a chocolate which is more resistant to melting at relatively high ambient temperatures and/or drier to the touch.
A variety of means have been utilized in the past to attempt to remedy the relatively low melting temperature of ordinary chocolate. For example, fats of higher melting temperature can be selected for incorporation into the chocolate.
However, this procedure can result in chocolate having undesirable mouthfeel, taste and/or texture. In fact, a composition that does not contain cocoa butter cannot be called xe2x80x9cchocolatexe2x80x9d in the United States under the Food and Drug Administration Guidelines.
Methods which disrupt the continuous chocolate fatty phase, thereby minimizing the influence of the melting point of the fat on the overall softening of the chocolate mass, have also been used. Such disruption of the continuous chocolate fatty phase has been effected in the past by various means, including direct water addition to the chocolate. Unfortunately, chocolate manufactured by direct water addition may exhibit inferior product quality due to a coarse, gritty texture. More importantly, the addition of water to chocolate results in a chocolate having extremely high viscosities, thus making the chocolate unsuitable for enrobing.
Disruption of the continuous chocolate fatty phase has also been effected by including a variety of particles in the composition, often solid particles. These processes unfortunately often result in an undesirable rough texture, or mouthfeel, in the chocolate. Moreover, the addition of any solids to the chocolate suspension will increase the viscosity of the system.
Swiss Patent No. 410,607 concerns a chocolate composition which contains hydrophilic substances such as dextrose, maltose, inverted sugar, etc. When chocolate is made with such a composition, it is exposed to a moist atmosphere whereby it absorbs a certain quantity of water. This causes a relative increase in the volume occupied by the hydrophilic substances and was said to improve heat resistance.
Additionally, Swiss Patent Nos. 399,891 and 489,211, are directed to a method of incorporating amorphous sugars into a chocolate composition during manufacture. The sugars cause the formation in the mass of a lattice structure which prevents collapse of the mass when the temperature exceeds the melting point of the fat bodies used in its preparation.
Swiss Patent No. 409,603 involves the direct incorporation of water into a chocolate composition during its manufacture. The water however, which is about 5% relative to the composition, causes a rapid thickening of the mass at temperatures where normally the mass is still a liquid. Unfortunately, since the mass is no longer liquid, it is not possible to use the composition to cast chocolate into molds. Thus, the composition must be ground and the obtained powder must be pressed into shape by compression molding.
U.S. Pat. No. 2,760,867 involves the incorporation of water into chocolate by the addition of an emulsifier such as lecithin.
U.S. Pat. No. 4,081,559 concerns the addition to chocolate of an amount of sugar such that when the quantity of water required to obtain heat-resistant chocolate is added, an aqueous sugar solution is formed in which at least one edible fat of the chocolate is emulsified.
U.S. Pat. No. 4,446,116 is directed to a composition used in the preparation of a heat-resistant chocolate article. However, the water-in-fat emulsion prepared in accordance with the teachings of this patent results in a product containing at least 20% of the fat in solid form, and the water-in-fat mixture used in accordance with this patent does not remain in liquid form during processing. Presence of such solid bodies results in an undesired rough texture or mouthfeel.
U.K. Patent specification 620,417 relates to the production of edible heat-resistant chocolate having a sugar skin produced by applying moisture to the surface of the chocolate to form a continuous skin of crystallized sugar over the chocolate. The resultant film is firmly interlocked with the chocolate surface preventing the film from chipping off or becoming detached. The moisture may be applied either while the chocolate, after tempering, is still plastic, or after it has frozen or set. The moisture can be applied by dipping the enrobed product into a water bath or subjecting the enrobed product to a mist or spray. Preferably, the pieces are subjected to an atmosphere substantially saturated with moisture. It is convenient to apply the moisture before the cooling apparatus. This reference discloses the use of high relative humidities, i.e., 90 to 95%.
Thus, the provision of a suitable method of making a heat-resistant or thermally robust enrobed chocolate, without substantially negatively affecting gloss or other attributes such as the taste, texture, mouthfeel, appearance or other important characteristics of the chocolate, or significantly reducing the efficiency of chocolate processes is a valuable addition to the art.
It is an object of the present invention to overcome the above-mentioned difficulties in the prior art.
It is another object of the present invention to provide improved methods for setting chocolate that provide improved enrobed and/or deposited chocolate confectionery products.
It is another object of the invention to provide improved enrobed chocolate products having enhanced bloom resistance, increased resistance to heat damage while maintaining good gloss and/or other advantageous characteristics.
It is a further object of the present invention to provide a method of setting chocolate within a shorter period of time and/or using shorter cooling tunnels.
It is a further object of the present invention to provide a means for the retention of fine detail and decoration on chocolate confectionery products.
It is a still further object of the present invention to provide methods of setting chocolate which may utilize ultra-low temper chocolate compositions.
It is an additional object of the present invention to provide a method of setting chocolate which results in a chocolate having higher resistance to fat bloom and potentially higher gloss.
It is yet another object of the present invention to provide a method of producing a chocolate having enhanced resistance to melt or heat damage.
It is a still further object of the invention to provide a method of setting chocolate using less fat in the chocolate composition without the detrimental increases in processing viscosity.
It is a still further object of the invention to provide a cooling tunnel which allows for the use of very low temperatures and/or very high heat transfer rates.
These and other objects and advantages of the present invention will become further apparent from the teachings hereinafter provided by the detailed description, test data, and examples.
The present invention relates to improved methods of making chocolates and improved chocolate products made using same. The invention departs completely from what was previously believed by chocolatiers in the art. Rather than gently or passively cooling chocolates, the present invention relates to methods which utilize fast and aggressive cooling to form a set chocolate.
According to one aspect of the invention, melted chocolate is rapidly cooled thereby setting the chocolate by solidifying at least a portion of the liquid fat phase into a stable form, i.e., polymorph form V or greater. The melted chocolate is set by rapidly cooling to form a solid set chocolate. The resultant rapidly cooled chocolate has many improved properties including enhanced gloss, improved bloom resistance and hardness. It is believed that the rapid cooling results in a solidified fat matrix having smaller fat crystals.
The cooling zone(s) used during the present invention provides for a more aggressive cooling and thus cools the chocolate more rapidly. Conventional non-mold cooling methods typically require greater than 7 minutes for setting. The rapid cooling of the present invention preferably results in the setting of chocolate in about 5 minutes, and even as low as 1.0 minute. The rapid cooling is achieved without the use of chilled plungers or cold molds, but instead utilizes increased convective heat transfer coefficients and/or lower operating temperatures.
Chocolate products produced by methods involving rapid cooling have a higher resistance to fat bloom and other advantageous properties including enhanced gloss. Moreover, the rapid cooling allows for the improved retention of fine detail and/or decoration on the chocolate product.
One particularly preferred embodiment relates to rapid cooling after enrobing the melted chocolate onto a food product. This provides an improved chocolate enrobed product with an enhanced resistance to bloom.
The melted chocolate composition set by the rapid cooling can be of conventional temper, low temper or ultra-low temper chocolate. Accordingly, another aspect of the invention relates to the ability to set low and ultra-low temper chocolate and still result in a stable finished chocolate product. Surprisingly, it has been discovered that rapidly cooling the melted chocolate allows for the use of a chocolate that has very little temper. In such a chocolate, the solids load in the system is decreased allowing for decreased viscosities to facilitate processing. For example, a low temper chocolate has less fat crystallized, i.e., more liquid fat and less solidified fat. This allows the chocolate composition to be processed, by enrobing or pumping through an apparatus, without the increases in viscosity typically associated with conventionally tempered chocolate. The ability to set chocolates having low and ultra-low temper levels are surprising and unexpected advantages of the presently disclosed rapid cooling. In fact, the chocolate compositions which were successfully processed using the invention were of such low temper that new methods of measuring these low temper levels were required.
A still further aspect of the invention relates to shearing a chocolate that has little or no temper immediately prior to, or immediately after, the initiation of rapid cooling to form a stable set chocolate having the characteristics of a set chocolate formed using conventionally tempered chocolate. The use of no temper chocolate provides the ability to work with chocolate compositions at processing, i.e., enrobing temperatures having even further decreased viscosities at any given fat content.
Yet another aspect of the invention relates to the use of a rewarm zone having high heat transfer rates after the cooling zone. This allows not only the ability to increase the speed of processing lines, but also results in chocolate products having further improved properties such as even further improved bloom resistance and gloss.
Yet another aspect of the invention relates to a method of using a controlled humidity environment in a rewarm zone after the cooling zone to form a thermally robust chocolate product having enhanced resistance to heat abuse, yet which still has good gloss. The resultant product has a drier, less greasy surface texture.
A still further aspect of the invention relates to slow warming of the set chocolate to room temperature to form a chocolate having additional advantageous characteristics including further improved and/or consistent gloss and enhanced resistance to fat bloom. It is believed this results in a fat crystalline structure having even finer fat crystal sizes.
Another aspect of the invention relates to cooling systems and apparatuses designed to provide the presently claimed rapid cooling.